Abstract: A lined pipe includes an outer layer and an inner layer. The outer layer contains crosslinked polyethylene, polypropylene, poly(1-butene), or poly(vinyl chloride). The inner layer contains poly(phenylene ether), polystyrene, and, optionally, a hydrogenated block copolymer. The inner layer exhibits low stimulation of bacterial growth. Also described are a composition exhibiting low stimulation of bacterial growth, an injection molded article, and a method of controlling microbial growth during transportation or storage of water.

Abstract: A method of forming a polyamide composition includes melt blending specific amounts of a poly(phenylene ether) masterbatch, a first polyamide, glass fibers, and a flame retardant that includes a metal dialkylphosphinate. The poly(phenylene ether) masterbatch is prepared by melt blending specific amounts of a poly(phenylene ether) and a second polyamide. The method provides a polyamide composition with a desirable balance of flame retardancy, melt flow, heat resistance, and mechanical properties, while reducing the amount of metal dialkylphosphinate required by corresponding compositions without the poly(phenylene ether) masterbatch. A corresponding polyamide composition is described, as are the poly(phenylene ether) masterbatch, and a method of reducing the metal dialkylphosphinate content of a flame retardant polyamide composition.